The prototype theory is a cognitive science theory developed by Eleanor Rosch in the early 1970s, with help from other experts in the field of cognitive psychology. In Rosch's theory, people categorize items and concepts based on a prototype or ideal representation of that category. For example, the concept of dog is often characterized by fur, a tail, and paws. When discussing or thinking about dogs, people think of classic, stereotypical examples such as collies or spaniels, because these represent the prototype. While a wolf or coyote might meet also meet the criteria of a dog, these animals are not prototypical of a dog.
According to the prototype theory, certain features of a category have equal status, and thus, examples that represent all or most of those features become the prototype for that category. Items that do not share the majority of these features may still belong to that category, but do not represent the prototype. Consider a category such as furniture. Features of furniture include wood, upholstery, seating, storage capacity, legs and arms, among many others.
Chairs may, to some individuals, be prototypical because these items of furniture have a majority of the common furniture features. A footstool, on the other hand, may not serve as a prototype because, while it has some common furniture features, it does not have a majority of those features. How each person applies prototype theory to categorizing concepts and language varies based on experience and cognitive development, although many individuals share similar categorizations.
Primarily, the prototype theory deals with how individuals categorize and stereotype certain items in language. Such understandings help psychologists understand and study the acquisition of vocabulary, individual mental lexicons, and the development of linguistic skills in individuals. Teaching environments, such as primary schools, benefit from such research and understanding when developing curricula for students. Understanding how the mind categorizes and classifies information, as well as how that process is affected by cognitive development, culture, and early learning experiences, aids in helping students gain vocabulary and develop more advanced language skills.
Under prototype theory, experts believe that a person's first experience with a particular stimulus later defines the prototype associated with that category of stimuli. As experiences are gained and a person is more exposed to a particular category, the prototype evolves into a central representation for that category. To put it in simple terms, a child's first experience with a bird might be a robin, and thus the child's prototype for birds becomes a robin. Through experience and exposure to other birds, her prototype comes to represent creatures with feathers, beaks, and the ability to fly, and can begin to include more birds like bluejays, eagles, and robins. An ostrich or a penguin may still be categorized as a bird, but because these species do not fly, they are not a representative example when the child initially talks of birds.